BREAKING: A third person unaccounted for after the Rozelle explosion has been named as Chris Noble.

Police said the search is continuing for the 30-year-old as well as Bianka O'Brien and her toddler, Jude.

It could still be many hours until firefighters and police have completely searched the site of Thursday morning's devastating explosion in Rozelle.

Emergency services described the mission as still one of "search and rescue" and said the effort was "painstaking".

2:24pm on 4 Sep 2014

John O'Brien and his baby boy, Jude, who is missing in the Rozelle explosion. Photo: Facebook

The search continues for Bianka O'Brien and her son, Jude, after the explosion at Rozelle at 4.06am on Thursday.

It is understood husband and father John O'Brien was not home at the time. He was being comforted by a work colleague after learning his wife and baby boy had still not been accounted for on Thursday afternoon.

A distressed Mr O'Brien has spoken with police.

The proud father shared a photo of himself and his son on Facebook recently, holding the grinning baby during his first ferry ride.

2:19pm on 4 Sep 2014

Emergency services have held another press conference at the scene of the explosion in Rozelle.

They described the mission as still one of "search and rescue" and said the effort was "painstaking".

Latest report: A mother and her little boy who are still unaccounted for after an explosion at Rozelle have been identified as Bianka O'Brien and her 12-month-old son, Jude.

It is believed Ms O'Brien is the sister of James Keremelevski, who owns a mobile phone store next to a convenience store that was obliterated by the explosion on Darling Street just after 4am on Thursday.

A mother and her 12-month-old son who are still unaccounted for after an explosion at Rozelle have been identified as Bianka O'Brien and her child, Jude.

It is believed Ms O'Brien, 31, is the sister of James Keremelevski, who owns a mobile phone shop next to the convenience store that was obliterated by an explosion on Darling Street just after 4am on Thursday.

Police said a 30-year-old man who also has not been accounted for was not a relative of Ms O'Brien and her baby boy.

In the past few months, a doting Ms O'Brien shared beautiful portraits of her son with her friends online.

She also posted many loving pictures with her husband, John.

In recent months, the couple had taken their son on his first ferry ride and spoke about how well-behaved he was.

"John was a good baby, so I would say Jude is just like him," she posted on Facebook.

11:12am on 4 Sep 2014

Three people remain unaccounted for following the blast in Rozelle this morning. They are a 31-year-old woman; a one-year-old boy, believed to be the woman's son; and a 30-year-old man.

Click here for the full story about this morning's devastating explosion.

11:03am on 4 Sep 2014

A map of where the explosion occured.

Resident Jessica Davis, who lives diagonally opposite the site of the explosion, said she and her boyfriend woke up suddenly when they heard a loud "bang" about 4am.

They watched the front of the shop collapse from the force of the fire.

"The building just fell down in front of all the firefighters," she said.

"It was really frightening.

"All the neighbours came out and people were still in their pyjamas."

Ms Davis said while she knew many of the shop owners along the street, the convenience store had recently changed hands.

10:52am on 4 Sep 2014

Darling Street is expected to remain closed between Victoria Road and Beattie Street in Rozelle for the rest of the day at least.

Transport for NSW says buses have been diverted, while passengers can also use their bus tickets on F3 Parramatta River or F4 Darling Harbour ferry services. Details are below.

For bus diversions in Rozelle due to the building fire on Darling St -visit: http://t.co/UevqZXUziR Tickets can be used on F3 & F4 ferries.